Our goal is to develop a fully automated ultra-high throughput radiation biodosimetry workstation, using purpose-built robotics and advanced high-speed automated image acquisition. Maximum throughput will be 30,000 samples / day, compared with throughputs in current devices of a few hundred samples / day. The basic system involves the well-characterized micronucleus assay in lymphocytes, with all the assays being carried out in-situ in multi-well plates. * By calling up pre-programmed options in timing, liquid handling, and image analysis, the device will also measure gamma-H2AX foci yields, and micronucleus yields in reticulocytes, both providing "same-day answer" dose estimates. * By calling up pre-programmed options in liquid handling steps, the device will also measure micronuclei in other readily-accessible tissues, such as exfoliated cells from urine or buccal smears. A key option of the system will be that each lymphocyte sample will be split in two, with one of the two split samples being irradiated to a dose of 1.8 Gy, before being analyzed. This will allow a positive control for each individual, providing an internal calibration to take into account inter-individual variability in radiosensitivity. We will develop both a Phase 1 and a Phase 2 device, with a 12-18 month lag between them: * The Phase 1 device, using 96-well plates, will have a throughput of 6,000 samples (3,000 individuals) per 15 hour day, and will use monochrome imaging. Peripheral blood drawn by venipuncture will be used. * The Phase 2 device, using 384-well plates, will have a throughput of 30,000 samples (15,000 individuals) per 15 hour day, and will use color imaging. Capillary blood from a finger stick or a high-throughput laser skin perforator will be used. Our Specific Aims, which will run in parallel throughout the project are 1) product development, and 2) the optimization / calibration / testing of biological protocols. Mass radiological triage will be critical after a large-scale event because of the need to identify, at an early stage, those individuals who will benefit from medical intervention, and those who will not. Our goal is to develop a fully automated ultra-high throughput biodosimetry workstation product (30,000 samples/day), using purpose-built robotics and advanced high-speed automated image acquisition.